Modern devices such as mobile telephones and tablet computers have developed with extremely fast pace during last decades. First GSM phone calls were made only about 20 years ago. Since then, mobile phones have become miniaturized computers, often equipped with touch screens, compasses, satellite navigation, multi-band radios, cameras, gyroscopes for automatic display orientation changing or muting ringer sound on incoming call by turning the display down, modems capable of megabits a second data rates and even flash lights that double as torches.
Various improvements have also been made in the usability of devices. First devices of various types, such as cameras and mobile telephones, had dedicated buttons for each function. Since then, displays capable of presenting menus and menu selection keys reduced the number of buttons and/or availed the user of more functions. More recently, touch screens have shifted the user interfaces further from hierarchical menu trees towards a flat structure in which one or more pages host large number of icons representing different functions, services or applications.
One new development that has been demonstrated with prototype mobile phones is flexible devices that users can use e.g. for entering user input. The flexible devices have become possible to construct in result of a number of different technical advances, such as development of flexible display screens. There are yet number of challenges that have made mass production and/or reliability of the flexible devices impractical. New techniques are needed for addressing these problems or at least for providing new technical alternatives.